Several nucleosides are now known which contain a carbon to carbon linkage between the sugar and aglycon portion of the molecule. Examples of such "pseudo" compounds include pseudouridine (5-(beta-D-ribofuranosyl)uracil, Shapiro et al., J.Am.Chem.Soc., 83, 3920 (1961) and pseudocytidine, Michelson et al., Biochemistry 1, 490 (1962).